If you are in search for a perforated plate (Lochblech) from stainless steel (Edelstahl) or from other metals, today many online stores in Germany provide the fabrication of various metal parts according. You can order an aluminium checker plate (AluminiumRiffelblech), stainless steel perforated sheet (lochbleichEdelstahl), galvanized sheet metal (vezinktesblech) and so no according to your configurations.
https://www.blechmal.de